Such a folding table is for example known from EP 1 836 927 A1. This table has a lower housing and a tabletop, which can be moved from a stowing position arranged vertically in the lower housing, into a usage position, in the case of which the tabletop is arranged substantially horizontally. The lower housing has a cover, which is folded out for pulling out the tabletop. A supporting frame for the tabletop is fastened in an articulated manner to supporting arms, which can be slid in lateral guiding rails via sliding frames. The pivot angle of the supporting frame relative to the supporting arms is limited by arcuate guides. The supporting frame can thus not be pivoted downwards past the horizontal usage position. In addition, four supporting arms are provided, the one ends of which are pivotably connected to the supporting arms, and the other ends of which are arranged so as to be capable of being slid in guides on the supporting frame. The pull-out of the table construction is supported against the force of gravity by springs.
In the prior art, the guiding of the tabletop when being pulled out is thus disadvantageously separated from the fold-down mechanism into the usage position. Separate motion sequences are thus provided, which are not very intuitive and ergonomic. The construction effort is furthermore also increased by the larger number of joints. Stability losses can further appear.
Further embodiments of folding tables are described in US 2009/0078169A1, US2003/0188672 A1, U.S. Pat. No. 2,536,366 and FR 2 802 070.
It is the object of the invention to reduce or to eliminate, respectively, the disadvantages of the prior art. This object is solved by means of a folding table comprising a supporting device for a tabletop, in particular for an aircraft, comprising a pull-out device for moving the supporting device for the tabletop from a substantially vertical stowing position into a substantially horizontal usage position via a substantially vertical pull-out position, wherein the pull-out device has a guiding device for guiding the supporting device between the stowing position and the pull-out position, wherein the guiding device has a substantially linear first guide track for a first guide element on the supporting device and a second guide track for a second guide element on the supporting device, which second guide track has a linear segment and an arcuate segment, wherein the supporting device is slid along the linear segment of the second guide track of the guiding device from the stowing position into the pull-out position and is pivoted from the pull-out position into the usage position along the arcuate segment of the second guide track of the guiding device, wherein the arcuate segment of the second guide track of the guiding device has a central angle of substantially 90°, wherein, in response to sliding the second guide element along the arcuate segment of the second guide track, the supporting device, together with the table top fastened thereto, is pivoted about the same angle of substantially 90°.
According to the invention, the guiding device has a substantially linear first guide track for a first guide element on the supporting device and a second guide track for a second guide element on the supporting device, which second guide track has a linear segment and an arcuate segment, wherein the supporting device can be slid along the linear segment of the second guide track of the guiding device from the stowing position into the pull-out position and can be pivoted from the pull-out position into the usage position along the arcuate segment of the second guide track of the guiding device.
The guiding device according to the invention thus has a first guide track, which runs in a straight line or linearly, respectively, substantially across the entire length thereof, and, on the other hand, a second guide track, which has a linear segment and, directly following the latter, an arcuate segment. In the first guide track, a first guide element is supported, which is coupled to the supporting device, in particular a supporting arm of the supporting device, at a first location. In the second guide track, a second guide element is supported, which is coupled to the supporting device, in particular the supporting arm of the supporting device, at a second location. The distance between the first location and the second location is preferably substantially constant. In response to the pull-out process, the first and second guide element wander along the first or second guide track, respectively. When the second guide element reaches from the linear segment into the arcuate segment, the supporting device is pivoted according to the course of the arcuate segment of the second guide track. The position of the supporting device is determined for each pivot angle due to the simultaneous guiding of the supporting device via the first guide element at the linear first guide track. Advantageously, a positive guiding of the supporting device for the tabletop from the stowing position via the pull-out position into the usage position (and vice versa) is thus attained. The embodiment according to the invention is characterized by a parts-saving and thus cost-efficient design. The pull-out or folding up process, respectively, can furthermore be designed in a intuitive and ergonomic manner. A particularly stable embodiment can further be attained. The embodiment according to the invention is furthermore in particular suitable to accomplish the fold-out of the tabletop by means of a single drive unit for the pull-out and pivoting process.
To effect a positive guiding of the supporting device between the substantially vertical pull-out position and the substantially horizontal usage position of the tabletop, it is favorable, when the arcuate segment of the second guide track of the guiding device has a central angle of substantially 90°. The arcuate segment of the second guide track thus describes an angle of substantially 90°, while the corresponding segment of the first guide track runs substantially linearly. In response to sliding the second guide element along the arcuate segment of the second guide track, the supporting device, together with the table leaf fastened thereto, is pivoted about the same angle of substantially 90°.
To support the tabletop on opposite sides, it is advantageous, when the pull-out device has two guiding devices for guiding one supporting arm each of the supporting device. Both guiding devices are preferably embodied substantially identically. On the one hand, each guiding device thus has a first guide track comprising a linear course, in which a first guide element, which is connected to the supporting device, can be slid. Each guiding device furthermore has a second guide track, in which a second guide element, which is connected to the supporting device, can be slid. The second guide track in each case has an arcuate or curved second segment, respectively, by means of which the pivoting of the supporting device between the pull-out position and the usage position is accomplished. The first and second guide element are connected to the supporting arm of the supporting device at different longitudinal positions. The positive guiding of the supporting device or of the tabletop fastened thereto, respectively, can thus be attained.
With regard to a structurally simple embodiment, which can be produced in a cost-efficient manner, it is advantageous, when a plate element, on which the first and the second guide track are embodied, is provided as guiding device. The first and the second guide track are preferably provided adjacently on the plate element. The first guide track is preferably formed by an elongated passage opening of the plate element comprising a substantially constant width, so that the first guide element protrudes from the side of the supporting device through the passage opening onto the side of the plate element, which faces away from the supporting device. In contrast, the second guide track can be formed by a depression of the plate element, in which depression the second guide element, in particular a guide pin, which is rigidly connected to the supporting device, is guided.
For automatically pulling out and pivoting the tabletop from the stowing position, it is favorable, when the guiding device is connected to a drive unit, preferably an electric motor, by means of which the supporting device can be moved from the stowing position to the usage position via the pull-out position. It is particularly preferred, when a single drive unit is provided in order to initially slide the supporting device from the stowing position into the pull-out position and then to pivot the supporting device from the pull-out position into the usage position. This embodiment is made possible in that the guiding device initially effects a positive guiding of the supporting device along the linear segments of the first and second guide track and then along the arcuate segment of the second guide track, while the first guide track continuous its linear course.
According to a preferred embodiment, the drive unit is equipped to move the first guide element along the first guide track of the guiding device, wherein the second guide element is preferably guided passively along the second guide track of the guiding device. In the case of this embodiment, the first guide element is driven, whereas the second guide element is guided passively, i.e. without its own drive, along the second guide track.
To provide for the pull-out and pivoting of the tabletop by means of a particularly simple, reliable drive unit, it is favorable, when the drive unit is equipped to set the first guide element into rotation, wherein, on the supporting device, the first guide element is connected to a power transmission element, by means of which the rotation of the first guide element can be converted into a linear movement of the first guide element along the first guide track. The drive unit is thus connected to the first guide element, which, in the driven state, performs a rotation. The drive unit is preferably located directly on the first guide element, which is embodied as drive shaft in this embodiment. According to a preferred embodiment, two guiding devices are provided on opposite sides of the folding table, wherein the first guide element, which is embodied as drive shaft, is used for both guiding devices. In the case of this embodiment, it is furthermore favorable, when the supporting device, in particular a supporting arm of the supporting device, is rotatably connected to the first guide element. In the case of this embodiment, a power transmission element is further provided, which absorbs the rotation of the first guide element and transforms it into a sliding of the first guide element along the first guide track.
The sliding of the first guide element can be accomplished in a particularly safe and reliable manner, when a gearwheel is provided as power transmission element, which gearwheel meshes with a toothed rack in response to the movement of the first guide element along the first guide track, wherein the toothed rack preferably has substantially the same length as the first guide track of the guiding device. In the case of this embodiment, the gearwheel is preferably connected to an end of the first guide element in a rotatably fixed manner. It is particularly preferred, when the first guide element is used for two guiding devices on opposite sides, wherein each end of the first guide element is connected to a gearwheel, which runs on a corresponding toothed rack. The first guide element preferably passes through a passage opening of the guiding device, which passage opening forms the first guide track, to the side of the guiding device, which faces away from the supporting device. In the case of this embodiment, the end of the first guide element, which passes through, is connected in a rotatably fixed manner to the gearwheel, which engages with the correspondingly formed toothed rack. In the driven state of the first guide element, the gearwheel thus wanders upwards or downwards, respectively, along the toothed rack, depending on the drive direction.
To be able to accomplish the move between the stowing position and the usage position of the tabletop with the smallest possible power drain of the drive unit, a spring element, which counteracts the pivoting of the supporting device in the direction of the usage position and/or which supports the pivoting of the supporting device from the usage position in the direction of the pull-out position, is provided according to a particularly preferred embodiment. In response to the pivoting of the supporting device from the pull-out position into the usage position, the spring element is tensioned under the influence of the dead weight of the supporting device or of the tabletop, respectively. In the usage position, the spring element is thus present in the tensioned state. In response to the pivoting of the tabletop from the usage position into the pull-out position, the stored tensioning energy of the spring element is released, in order to support the lifting of the supporting device along with the tabletop. In the pull-out position, the spring element is preferably present in the relaxed state.
A further spring can furthermore be provided, by means of which the sliding of the supporting device from the stowing position into the pull-out position is supported. In response to the sliding of the supporting device from the pull-out position into the stowing position, the further spring is tensioned. A helical spring is preferably provided as further spring, which is tensioned or relaxed, respectively, by means of a rotation of the first guide element.
In order to provide the spring force in response to folding out or folding in the tabletop, respectively, in sections, it is favorable, when the spring element is connected to a pivot lever, which can be pivoted against the force of the spring element by means of the first or the second guide element on the supporting device. On one end, the pivot lever is supported about a stationary pivot axis, which preferably extends substantially in the horizontal direction. The one end of the spring element, the other end of which is supported in a stationary manner, engages on the other end of the pivot lever. During its guided movement, the first or the second guide element thus strikes against the pivot lever in the direction of the usage position. In the struck state, the pivot lever is pushed upwards by means of the first or second guide element, respectively, wherein the spring element is tensioned with the support of the weight of the supporting device along with the tabletop. In response to the pivoting of the supporting device together with the tabletop from the usage position into the pull-out position, the tensioning energy of the spring element is transmitted via the pivot lever to the first or second guide element, respectively, so that the lifting of the supporting device together with the tabletop is supported. In the phase of highest load, the drive unit can thus be supported with the pretensioned pivot lever as a result of the dead weight of the supporting device or of the tabletop, respectively. This embodiment has the advantage that the maximum drive force, which is to be provided by the drive unit, can be reduced. A comparatively weak drive unit can thus be used in order to pivot the supporting device together with the tabletop upwards from the usage position into the pull-out position. During the sliding of the supporting device between the storage position and the pull-out position, the spring element is preferably present in the relaxed state.
According to a particularly preferred embodiment, the distance between the point of application of the first or second guide element, respectively, on the pivot lever and the pivot axis of the pivot lever is larger in the case of a first pivot angle of the supporting device in response to pivoting from the substantially vertical pull-out position in the direction of the substantially horizontal usage position, than in the case of a second pivot angle of the supporting device. In the case of this embodiment, the force transmission from the pivot lever to the first or second guide element, respectively, which struck said pivot lever, is thus a function of the pivot angle of the supporting device. The variable force transmission results from the lever relationships between the pivot leer and the first or second guide element, respectively, which engage therewith. The larger the distance between the point of application of the first or second guide element, respectively, on the pivot lever and the pivot axis thereof, the smaller the torque, which the pivot lever transmits to the first or second guide element, respectively. In response to pivoting the supporting device upwards from the usage position, the drive unit can thus be maximally supported specifically in the phase of highest load effect.
For this purpose, it is furthermore favorable, when the distance between the point of application of the first or second guide element, respectively, on the pivot lever and the pivot axis of the pivot lever is larger in the case of a third pivot angle of the supporting device in response to pivoting from the substantially vertical pull-out position in the direction of the substantially horizontal usage position, than in the case of the second pivot angle of the supporting device. In response to pivoting the supporting device from the pull-out position into the usage position, the pivot lever in the struck state of the first or second guide element, respectively, is pivoted against the force of the spring element, wherein the arm of the force, which is formed between the first or second guide element, respectively, and the pivot axis of the pivot lever, varies, depending on the pivot angle of the supporting device.
In the case of this embodiment, it is further preferably provided for the first pivot angle of the supporting device to be smaller than the second pivot angle of the supporting device, which is smaller than the third pivot angle of the supporting device. In response to pivoting the supporting device from the pull-out position into the usage position, the supporting device consecutively runs through the first pivot angle, the second pivot angle, and the third pivot angle, wherein the force transmission from the spring-loaded pivot lever to the first or second guide element, respectively, reaches a maximum with the second pivot angle.
To return the pivot lever into the first angularity in response to folding up (folding in) the supporting device, it is favorable, when the pivot lever is pretensioned in the direction of a first angularity, which corresponds to the first pivot angle of the supporting device, by means of the spring element, wherein a stop element for limiting the pivoting of the pivot lever to the first angularity is provided.
So as to be able to adjust the spring characteristic in response to the pull-out or pivoting process, respectively, it is favorable, when the stop element is connected to a control element, in particular an adjusting screw, by means of which the first angularity of the pivot lever can be adjusted.
If at least two fastening locations, which are spaced apart from one another in the longitudinal direction of the first guide track, are provided for the selective arrangement of the pivot axis of the pivot lever, the point in time, at which the force transmission from the pivot lever to the first or second guide element, respectively, starts, can be changed.
According to a first preferred embodiment, the substantially linear first guide track of the guiding device and the linear segment of the second guide track of the guiding device extend substantially in the vertical direction.
For the purpose of this disclosure, the information about location and direction, such as “horizontal”, “vertical”, “upper”, “lower”, etc., refers to the assembled usage state of the folding table, when being used in an aircraft, it refers to the horizontal bottom surface of the aircraft.
In the case of this embodiment, it is favorable, when a cladding element is provided, which can be pivoted between a position, which closes a pull-out opening for the supporting device, and a position, which releases the pull-out opening for the supporting device. The cladding element can preferably be pivoted about a substantially horizontal pivot axis. The cladding element can form the upper side of a housing, by means of which the folding table is installed in particular into an armrest or a side cladding of an aircraft.
To design the operation to be particularly simple, a switch for activating the drive unit is preferably provided, which switch can be operated by pivoting the cladding element. In the case of this embodiment, the cladding element can strike against the switch or can be lifted off it, respectively, in order to initiate the pull-out process, starting in the stowing position. Vice versa, the switch can be operated via the cladding element, in order to initiate the fold-in process, starting in the usage position. The switch can be connected to the drive unit via a control unit for this purpose.
According to an alternative preferred embodiment, the pull-out device has a tilt mechanism for tilting the guiding device for the supporting device from the substantially vertical stowing position into an initial position, which is inclined relative thereto. In the case of this embodiment, a fixed or non-pivotable cladding element, respectively, can be provided on the upper side of the folding table, which cladding element, in the assembled operating state, is preferably arranged substantially horizontally. In order to bring the folding table from the stowing position into the usage position, the tilt mechanism, by means of which the at least one guiding device is tilted about a preferably substantially horizontal pivot axis, is initially activated. The supporting device can then be moved from the stowing position into the usage position via the pull-out position by means of the drive unit, wherein, in the tilted state, the supporting device together with the tabletop can be guided past the immovable cladding element. In the case of this embodiment, a switch can also be provided, which is connected to the drive unit via a control unit. For example, a push switch can be provided on the fixed cladding element.